HIVE-6605 : Hive does not set the environment correctly when running in Tez mode (Sergey Shelukhin, reviewed by Gunther Hagleitner and Siddharth Seth)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.13@1576454 13f79535-47bb-0310-9956-ffa450edef68